
%0 Journal Article
%A McCrabb, G. J. 
%A Berger, K. T. 
%A Magner, T. 
%A May, C. 
%A Hunter, R. A. 
%T Inhibiting methane production in Brahman cattle by dietary supplementation with a novel compound and the effects on growth
%J Australian Journal of Agricultural Research
%D 1997/03/27
%V 48
%N 3
%P 323-329
%K bromochloromethane, &#945;-cyclodextrin, voluntary roughage intake, feed conversion efficiency.
%R https://doi.org/10.1071/A96119
%U https://www.publish.csiro.au/paper/A96119 
%X Three experiments were conducted to determine the effects of dietary supplementation with a novel antimethanogenic compound (AM) on methane production and growth in Brahman (Bos indicus) steers. The compound was a chemical complex of bromochloromethane (BCM) and &#945;-cyclodextrin, which is chemically stable when added to feed, thus overcoming the highly volatile nature of BCM. In these experiments the AM compound was administered to steers as a mixture with different feed supplements. In Expt 1 the effect on in vivo methane production of feeding steers the AM compound was determined using a confinement-type respiration chamber. Methane production of AM-treated steers (0 &#177; 2&#183;4 mL/min) was lower (P &#60; 0&#183;001) than that of control steers (205 &#177; 5&#183;2 mL/min) over 28 days. In Expt 2 we determined the effect of AM treatment over 12 weeks on growth of steers fed on a low quality roughage diet. The most marked effect of AM treatment was reduced (P &#60; 0&#183;01) voluntary roughage dry matter intake (DMI), and reduced (P &#60; 0&#183;01) acetate : propionate molar ratio (A : P) in rumen fluid. Average daily liveweight gain (ADG) (0&#183;22 &#177; 0&#183;01 kg/day) and feed : gain ratio (F : G) (20&#183;7 &#177; 1&#183;46 kg DMI/kg liveweight) were not significantly affected by AM treatment. In Expt 3 we determined the effect of AM treatment over 10 weeks on growth of steers fed on a medium quality roughage diet, in steers that were either treated or not treated with a hormonal growth promotant (HGP; oestadiol 17&#946;). AM treatment reduced (P &#60; 0&#183;05) DMI below that of steers not treated with AM, whereas DMI was not significantly affected by HGP treatment. Both AM (P &#60; 0&#183; 1) and HGP (P &#60; 0&#183;05) treatments separately reduced A : P ratio in rumen fluid. AM treatment had no significant effect on ADG, whereas ADG of HGP-treated steers was higher (P &#60; 0&#183;05) than that of steers not treated with HGP (0&#183;76 &#177; 0&#183;27 v. 0&#183;60 &#177; 0&#183;027 kg/day). F : G was reduced (P &#60; 0&#183;01) by HGP treatment. F : G of both HGP-treated steers and those steers not treated with HGP was reduced (P &#60; 0&#183;05) by AM treatment. We conclude that feeding steers with this novel AM compound enables the potent antimethanogenic properties of BCM to be realised under commercial conditions, and that prolonged use over 10&#8211;12 weeks is associated with an improved feed conversion efficiency in steers fed on better quality roughage diets. 
